The process of monitoring the sentient state of a subject is an essential pre-requisite to reliable tracking of many physiological parameters or the effective clinical deployment of many monitoring systems.
Additionally, and in the context of general monitoring of physiological signals, the requirements to distinguish the source of a signal can be a critical step. In particular, a physiological monitoring system output measure typically relies upon the assumption that the output measure is predominantly based on a known source of interest. In the case of cerebral monitoring during anaesthesia, for example, output measurement indices relied upon as a basis for the determination of anaesthesia-depth can incorporate authentic neural signals of interest emanating from the central nervous system (CNS), electromyography signals emanating from muscle activity and generated by the peripheral control system (PCS), or artifact generated as a results of factors such as arousals, body movements, electrical noise or electromagnetic noise.
In the case of monitoring sentient state the determination of an individual's response to external stimulus can be representative of a unique aspect of consciousness state. In particular an individual's coherence with the environment or vigilance to external prompts, or in this particular case the response to an external stimulus provides important information regarding an individual's state of alertness from a safety or operational proficiency perspective. Furthermore, in the context of anaesthesia-depth, sedation or testing procedures such as hearing function determination, the sentient state of an individual can be crucial in terms of accurate interpretation of dosage guidance or hearing function.